Refrigerating apparatus



May 24,1927. 1,630,077

F. W. SCHWINN v REFRIGERATING APPARATUS Filed Oct. 19. 1925 3 Sheets-Sheet 1 f f Z? km @i @j my 24, 1927'a W. SCHWHNN REFRIGERATING APPARTUS M l www? ay 24 927 F. Wu SCHWHNN t REFRIGERATING APPARATUS Filed Oct. 19, 1925 3 Sheets-Sheet 5 Patented May 24, 1927.

PATENT OFFICE.

( FRANK W. SCHWINN, OF CHICAGO, ILLINOIS.

REFRIGERATING APPARATUS.

Application led October 19, 1925. Serial No. 63,384.

This invention relates to improvements in yrefrigerating apparatus;` and more especially to means for thermostatically cont-roh ling thepump-or compressor switch and the expansion valve. l.

Another feature ot my invention is a new and improved expansion valve.

In apparatus of this kind, the

pressor to an expansion valve, thence to the cooling coil, and back again to the compressor. The cooling coil is placed in the compartment to be cooled.

In order to Lmaintain the desired temperature in the compartment. to be cooled. I have provided thermostatically controlled means .or opening and closing the expansion valve. Whenthe temperature rises to a certain point such thermostatic means operates to open the expansion valve andpermit the How of the refrigerant. Upon `the temperature dropping to a desired point, such How is automatically shut otl' in order to prevent the compartment from becoming too cool.

I have also provided thermostatic means for shutting oli the pump or compressor when the expansion valve is closed. One of the principal features of `my invention is the provision of a single thermostatlc means for stopping the compressor and closing the eX- pansion valve when the temperature drops to a certain predetermined point. I have found that by both stopping the compressor and closing the expansion valve, it is possible to obtain a much more accurate regulation of temperature in the compartment to be cooled. It the compressor is merely stopped, there will be some after-flow ot refrigerant into the cooling coil causing a further drop in temperature beyond the desired point..v I overcome this after-flow by closing the expansion valve at the same` time that the compressor is stopped. I

Other features and advantages of my invention will appear more with my specification.

In that form ot device embodying the features of my invention. shown in the accompanying drawings. Figure 1 is a view, partly diagrammatic, showing a compressor, expansion valve, and thermostatlc switch, the expansion valve being shown in vertical section, Fig. 2 is a view of the expansion valve and thermostatic. switch in side elevarefrigeratkl lng llquid passes from the pump or com-v fully as I proceed tion, Fig. 3 is a View in vertical section showing a modified form of expansion valve, together with a thermostatic switch controlling the same, and Fig. 4 is a top plan view of the expansion valve shown in Fig. 3.

In the drawings,` I have not shown a complete refrigerating system, since such systems are well known in the art and in common usage. It is to be understood that such a system comprises in general, a compressor', a condenser' expansion valve, and a cooling coil located in the compartment to be cooled. vIn the drawings accompanying` this specification, I have not shown the cooling coil or the compartmentto be cooled, since the same are of well known construction.

As. shown in the drawings, 10 indicates diagramnmtically a pump or compressor, electrically driven, adapted to force a refrigerant through the pipe 11 to the condenser and thence to the expansion valve indicated in general by A. The refrigerant leaves the expansion valve through` the pipe 13 which leads to the cooling coil not shown. 14 indicates the return pipe to the compres- The expansion valve comprises a casting 12 having,r an inlet opening 15 at the bottom to which the pipe 11 is oined. 16 indicates a removable seat threaded into the upper end of the inlet opening'l. Lying on the valve seat 16 is a valve head 17 adapted to close the orifice 18 therein.

Arranged above the valve head 17 is a diaphragm 19 and lying above this is an arm 20 pivoted at 21 at one side of the diaphragm and extending diametrically across the same. The center part of the arm 20 is bent downwardly as indicated by 2()a diaphragm 19. The :free end of the arm 20 as indicated by 20" is provided with an adjusting screw, the lower end of which rests on the upper end 23 nf a rod carried by a temperature responsivev element 24:. of any desired construction.

The portion of the rod 23 intermediate its ends is threaded as indicated by 25 and carries thereon a nut 26 provided with an annular shoulder 27.

28 indicates a swinging arm pivoted at 32, carrying at having therein at one end the two electrical terminals 30, 30.A Within Vthe tube 29 isa drop of mercury' 31.

its lower end a. glass tube 29` to lie close to the The upper end of the arm 28 near the pivot 31 carries a short nose 33 lying adjacent the shoulder 27 on the nut 26. A spring 34 is adapted to yieldingly hold the lower end of the arm to the left (as viewed in Fig. 1). The two electrical terminals 30, 30 are connected to the two wires 30a and 30b which lead to the motor 10a adapted to drive the compressor 10. 30c indicates, diagrammatically, any source of electrical energy adapted to drive the motor 10a.

In the operation of the device, the temperature Vresponsive element 24 is placed in the compartment. to be cooled and the nut 26 is adjusted on the threaded part 25 so that the shoulder 27 will engage the nose 33 on the arm 28 and rock the same to cause the mercury 31 to flow toward the contacts 30, 30 and close the switch when the temperature in the compartment rises to a certain point. The adjusting screw 21 on the arm 20 is also so adjusted that at substantially the same time. the upward movement ot' the part. 23 carried by the temperature responsive element 24 will raise the central portion 20a of the arm 20 resting on the diaphragm 19 and permit the valve head 17 to rise and the expansion valve to open. The arm 20 is yieldingly pressed downwardly by a spiral spring 35 as shown.

It will be seen that when the temperature reaches a predetermined point the temperature responsive element 24 will raise the nut 26 and part 23 to close the electric switch and open the expansion valve as above described. The compressor will thereupon be started and the flow of refrigerant through the cooling coil will be permitted until the temperature drops to a certain point. "Upon the .temperature falling to a. predetermined point. the temperature responsive element 24 will contract, to lower the shoulder 27 and the part 23 permitting the spring 34 to swing the arm 28 to the left to open the electrical switch thus shutting oft' the electric current to the compressor. At the same time the arm 20 will be pressed down by the spring 35 against the diaphragm 19 thus pressing down the valve head 17 and closing the expansion valve.

In Fig. 3 I have shown a modified form of expansion valve which is electrically controlled by the temperature responsive element 24ar instead of mechanically. The general operation of the apparatus here disclosed is the same as that shown in Figs. 1 and 2. I have not deemed it necessary, therefore. to show any connection with this modified form of expansion valve. and compressor. It is to be understood that the two electric contacts 30, 30, of the electrical switch are provided with wires 30a and 30" leading to a compressor not shown. The construction and operation of the electrical switch is also the same as shown in Figs. 1

and 2 and, consequently', will not be described here in detail.

The expansion valve here shown is provided with an inlet orilice 36 having at its inner end a removable seat 37. 38 indicates a valve head adapted to close the orifice 39 in the removable seat. 37. Lying above the head 38 is a diaphragm 39,

Arranged above the dial'ihragrn 39 is a solenoid comprising the coil 4l) and movable armature 41. In the. lower side of the armature 41 is an adjusting screw 42 lying against the diaphragm 39. lThe armature' 4l is yieldingly pressed downwardly by the spiral spring 43. llnergization ot' the coil 40 raises the armature 4l to remove the pressure of the adjusting screw 42 from the diaphragm 39. 44 indicates any suitable source of electrical energy adapted to furnish current to the coil 40, the ends of the circuit being joined to the terminal 30, 30 of the electrical switch.

The screw 42 is adapted for upward or downward adjustment in the armature 41 by rotation of the same by means of the holes 45 provided therein.

ln the operation of the device shown in F ig. 3, the electrical switch indicated in general by B is placed in the compartment to be cooled. It is to be especially noted that in this form ot' device however, the expansion valve need not be placed in such compartment. The parts are so adjusted that when the temperature rises to a predetermined point, the temperature responsive element 24 will expand to cause the mercury 31 to close the contacts 30. 30 in the same manner as described in connection with the apparatus shown in Figs. 1 and 2. Closing of the contacts 30, 30 will start the compressor; and will also cause energization of the coil 40 to raise the arlnature 41 thus removing the pressure of the adjusting screw 42 from the diaphragm 39 and permitting the head 38 to rise and the expansion valve to open. ll'hen the temperature drops to the predetermined point, the electric switch will open whereupon the compressor will stop and current from the coil 40 heilig cut off, the spring 43 will force the adjusting screw 42 down against the diaphragm 39 and thus press it downwardly against the head 38 to close the expansion valve.

lVhile I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many n'iodifications. Changes, therefore, in the construction and arrangement may be made without departing,r from the spirit and scope of the invention as disclosed in the appended claims. in which it is my intention to claim all novelty inherent in my invention as broadly as possible inview of the prior art.

The spring 35 (see Fig. l) which presses down the arm 20 is held "t its upper end by the bridge piece 50. This bridge piece 50 also has threaded in it a screw 51 the lower end of which indicated by 51av Aextends throu h a hole in the arm 2() and acts as a stop or the upward movement of the diaphragm 19. The screw 51 can be adjusted upwardly or downwardly in the bridge piece 50 in order to vary the position of such stop and, consequently vary the maximum opening of the expansion valve. lock nut to hold the screw 51 in its adjusted position.

In the device shown in Fig. 3 the screw 42 is adapted for upward or downward adjustment 1n the armature 4l by rotation of the same. Such adjustment will vary the maximum` upward movement of the diaphragm 39 and consequently vary the maximum opening of the expansion valve.

52 indicates a.

What I claim as new, and desire to secure by Letters'Patent, is:

In refrigerating apparatus; an electrically driven compressor; a condenser; an expansion valve; a temperature responsive element exposed to changes in temperature in the compartment cooled by said refrigerating apparatus; and means, controlled by said temperature responsive element, for automatically mechanically controlling said expansion valve in accordance with changes in temperature in said compartment, and automatically electrically controlling the operation of said compressor in accordance with said changes in temperature.

In testimony whereof, I have hereunto set my hand this 30th day of September, 1925.

FRANK W. SCHWINN. 

